Incandescent electric lamp



Jan. 7, 1930. A. L; BECKET INCANDESCENT ELECTRIC mu" Filed June 19. 1925 Wm M INVENTOR.

. BY y ATTORNEYS Patented Jan. 7, 1930 ALAN L. BECKET, OF EAST ORANGE, NEW JERSEY mcmnscnm anagram LAME Application filed June 19,

This invention relates to an incandescent lamp in which a plurality of filaments are provided so that as soon as one filament burns out or breaks, the next one is available for use,

and so on until they are all utilized. By this invention, filaments are brought into use seriatim as soon as a preceding one breaks by means that operate automatically, and provision may be made for minimizing the danger of this means rupturing the filaments. Provision may also be made for automatically flashing the light by means operated by heat developed during the time the light is shining. This invention is especially adapted to incandescent lamps that are filled with gas,

such as nitrogen, for example, in which tungsten is used as to material of which the filaments are made, but it is not restricted to this particular sort of lamp.

The invention will be understood from the description and the accompanying drawings, in which Fig. 1 is a view in elevation, showing the invention; Figs. 1, 1", 1 and 1 show modified forms of the filament; Fig. 2 shows a modification of the invention and Fig. 3

shows a second modification. In the drawings, reference character 1 indicates the bulb of an ordinary incandescent lamp that is provided with the stem portion 2 through which the lead-in wires are sealed. Reference character 3 indicates a pair of lead-in wires which may be connected to. one side of a source of current. In this illustration, :2.

glass tube 4 is shown, through which the bulb may be exhausted of air, and as, such as nitrogen, introduced into the bu b. The leadin wire 5 passes through the tube 4 and is sealed against leakage, as shown at 6.

Instead of having two lead-in wires 3, as indicated, one wire may be used and may be divided into branches. The two spaced conducting elements 7 are disposed in the bulb, as indicated in the drawing, and are connected to the two respective lead-in wires 3. A

plurality of. electric light filaments 8 are connected between the elements 7 with their ends terminating in electrical contact with these elements. These filaments may be made zig zag of tungsten wire, or other suitable mate- 50 rial, for example, as shown at 8, or they may 1925. Serial No. 38,154.

in other suitable forms. The filaments may be wound so as to concentrate a large amount 7 of wire in a small space as shown at 85 and 86 in Figs. 1 and 1 in which the filaments are wound, respectively, as a series of 8s in close proximity to but not contacting with each other and a series of approximate 8s in which the wires do not cross at the middle.

The lead-in wire 5 is connected inside the lamp or terminates in a metal tube 9, into which, or alongside of which a movable contact member 10 extends. This member 10 may connect electrically to the tube 9 by merely contacting with the inner walls of this tube or by other means mentioned below. Member 10 maybe made in the form of a tube so as to slide freely upon member 9. In either construction a good electrical contact between the movable member 10 and the stationary contact 9 may be further insured by introducing within the tube various conducting elements such as'mercury for example. A small drop of mercury has a strong tendency to form itself into a sphere.

I The lower end of the contact member 10 terminates in a tip of suitable composition and shape for contact with the filament-s. It may, for example, be a cross piece 12. preferably concave on its lower side to contact with the filaments 8. The filaments 8 may, if desired. be provided intermediate their ends with contact portions, as shown at 13. Connection between the lead-in wire 5 and the filaments may be made through mercury or its alloys to decrease friction and resistance. For example, mercury may be confined in metal gauze fied form is illustrated, the contact member 10' is provided with a thin disc 14' of suitable light material, such as mica, that is fixed to the member 10'. I

I ment is hot.

I the light as soon as one filament In the modification shown in Fig. 3 in which only one filament 8 is shown, the tube 9" is provided near its lower end with a disc of insulating material 15. Guide rods 16,

are connected from the disc 15 to the connecting contact 13" of the filament 8,, and the disc of insulating material 14" which is attached to the contact member 10" is provided with holes 17 through which the rods 16 pass.

The operation is as follows: When the electric lamp is connected to a socket, in the usual manner, and the current is turned on, it passes from one source of the current through the lead-in wire 5, tube ".9, contact one and so on until all of the filaments are.

used up. It will thus be seen that one electric bulb equipped as described, will last as lon as several bulbs that are provided with slngle filaments.

. It is well-known that incandescent lights operate more efficiently at high temperatures. A light of the sort herein described may be operated at higher efficiencies than the usual light, because it is not necessary to replace urns out. The modification shown in Fig. 2 is especially suitable for gas filled lamps in which it is desired to reduce the pressure on the filaments, due to the weight of the contact member 10 during the time the fila- For this purpQse, the disc 14 is attached to the member 10 located near the axis of thebulb, so that the hot gases or convection currents which rise near the center of the bulb and pass downwardly near the inner surfaces thereof, sweep upwardly against the disc 14 and thereby tend to lift the same, together with the contact member 10', oil of the filaments. The disc 14 may be made of suflicient area and the parts may be sufiiciently li ht to enable the uprising gases to break t e contact, thus providing automatic flashing of the light.

In the modification shown in Fig. 3, the hot gases rising when the filaments are bot will impinge against the disc 14" and lift a the same, together with the contact element 10", a sufficient distance to break the circuit, the rods 16 through the bolts 17 in the disc guiding the disc in its upward movement. As soon as the temperatures of the gases in the bulb have become sufficiently equalized to permit circulation of the gases to slow down, the disc 14 will descend by gravity and contact will again be made, the

light will again light-,- and after a short interval, the contact will again be broken and the light extinguished by the hot gases again lifting the disc 14 It isto be understood that a plurality of filaments may be used in Figs. 2 and 3 in the same manner as above described in connection with Fig. 1.

It is obvious that instead of having the contact member 10 moved by gravity to make contact, a spring, such as a coil spring, for example, may be placed in the tube 9 to force the contact member 10 in a longitudinal direction. In order to avoid danger of hanging portions of broken filaments contacting with a lower filament, the successive filaments may be attached on alternate sides,-or in a staggered relation, upon opposite sides of the elements 7, or the successive filaments may be attached to the member 7 with distances therebetween greater than the length of broken arts of the preceding filaments.

It has bulb of such a shape as to provide a chamber for metal that evaporates from the filament and deposits upon the inner walls of the bulb.

'Ihisniay be done by making the bulb of elongated shape, as the convectlon currents cause the metal particles to be mechanically entrained and carried upwards and become deposited on the upper portion of the inside of the bulb. The successive filaments that are brought into operation by breaking of preceding filaments are progressively located away from the blackened region and are disposed opposite the portions of the bulb that have not become so greatly blackened by deposition of material from the filaments.

I claim 1. In an incandescent electric lamp, a plurality of parallel filaments in a vertical row, and automatic means for connecting the filaments following the first one into the circuit in succession as soon as the preceding one has become broken, said means comprising an elongated longitudinally movable element.

2. In an incandescent electric lamp, a row of filaments in a vertical row, and means to connect each one into the circuit when a pre-' of a filament to connect the next one into the circuit, said means comprising an elongated longitudinally movable element.

4. In an incandescent electric lamp, arow of filaments, and gravity operated means to connect each one into the circuit when a preceding one breaks, said means comprising an elongated longitudinally movable element.

5. In an incandescent electric lamp, a plurality of transverse, alined filaments in a 1,-m,eao

single 7 lane, and automatic means in the plane 0 said filaments for connecting the filaments following the first one into the circuit in succession as soon as the preceding one has become broken.

6. In an incandescent electric lamp, a plurality of filaments, automatic means for connecting the filaments following the first one into the circuit in succession as soon as the preceding one has become broken, and means operated by the heat from the filaments to reduce the force exerted upon said filaments by said connecting means.

7. In an incandescent electric lamp, a plurality of filaments, automatic means for connecting the filaments following the first one into the circuit 'in succession as soon as the precedingpone has become broken, and means operated the heat from the filaments to reduce the orce exerted upon said filaments by said connecting means suficiently to break the circuit.

8. In an incandescent electric lamp, a row of filaments in a single plane, and means insaid plane to connect each one into the circuit when a preceding one breaks,-saidconnection being such that current will flow in difierent directions through said filaments.

9. In a gas filled incandescent electric lamp, a plurality of filaments, automatic means for connecting the filaments following the first one into the circuit in succession as soon as the preceding one has become broken, and means operatedby the gas to reduce the force exerted upon said filaments by said connectin means.

10. In a gas led incandescent electric lamp, a plurality of filaments, automatic means for connecting the filaments following the first one into the circuit in succession as soon as the preceding one has become broken, and means operated by convection currents of gas caused by heat from said filaments to re uce the force exerted upon said filaments by said connecting means.-

11. In an incandescent electric lamp, a plurality of filaments, automatic means for connectin the filaments following the first one into t e circuit in succession as soon as the preceding one has become broken, and means operated by heat from said filaments to cause the current to be periodically interrep 12. In an incandescent electric lamp, a plurality of filaments the ends of which are connected to one side of a source of current,

and gravity operated means to connect an intermediate point of each filament to the other side of said source when a precedinig filament breaks, said means comprising a sli ing contact. I

13. In a gas filled electric lamp, a filament, and means operated by convection currents from said filament'to cause the current to be periodically interrupted. 

